There are many types of room air conditioners. For example, some air conditioners provide cooling and they typically also have the capability for venting by recirculating room air or also introducing fresh air from the outside. Other air conditioners provide heating such as by a fan blowing air past electric coils or past a heat exchanger such as supplied by forced hot water from a remote source. Other air conditioners have the capability of providing a plurality of operational modes such as heating, cooling, and venting in one unit. Further, air conditioners are manufactured for a variety of installation categories such as free standing, wall mounted or window mounted. Regardless of the type or category of room air conditioner, however, one characteristic that is common to most is that each generally has a control panel which is used to set the operational parameters such as mode, fan speed, temperature, or vent.
In many applications, it is desirable to prevent unauthorized access to the control panel. For example, in schools, motels, and offices of business and Government, it may be desirable that the temperature and other operational parameters of an air conditioner be set by a building custodian as part of an energy efficiency plan. In such case, it may be necessary to limit access to the control panel so as to prevent unauthorized people from changing the preset operational parameters.
Many room air conditioners have an opening in the air conditioner enclosure and the control panel is recessed below the opening. Frequently, a hinged door or lid is provided to improve the appearance of the unit; the lid may also serve to ease cleaning and prevent inadvertent bumping of the control knobs. The standard prior art approach to preventing unauthorized access to the control panel is to put a lock on the lid. Conventionally, an aperture is cut in the lid and a key lock with a rotating latch member is mounted. Only those having the key can unlatch the latching member to open the lid and gain access to the control knobs. This approach, however, has disadvantages. First, to retrofit air conditioners already in the field, the aperture in the door must be drilled for mounting the lock; this normally requires proper tools and a trained technician. Also, a groove for receiving the latch member may have to be provided. Second, if the lock is to be added to the door during manufacturing, different models have to be provided and inventoried because many applications do not require a locked door and many consumers wouldn't want it.